Objective To evaluate the role of contrast-enhanced color Doppler ultrasonography with Levovist in the diagnosis of liver tumors.Methods One hundred and twenty-five patients with 126 hepatic solid lesions were examined by conventional color Doppler and contrast enhanced ultrasonography.All hepatic lesions were confirmed by pathology.Of these,79 cases with hepatocellular carcinoma,4 cases with metastatic liver carcinoma,13 cases with hemangioma,7 cases with inflammatory pseudotumor of liver,7 cases with focal nodule hyperplasia,and 15 cases with other benign lesions.The Levovist with a concentration of 400 mg/ml was injected into an antecubital vein within approximately 2 minutes.Results All hepatic solid lesions with blood supply were differently enhanced by contrast-ultrasonography (I～IV grades).The color flow signals with grade III and grade IV were detected in one malignant lesion before contrast-enhancement and in 41 malignant lesions ( 49.4%) after contrast-enhancement.The color flow signals were detected by contrast-enhanced sonography in 26 malignant lesions ( 92.8%) with no color Doppler signals and in 33 benign lesions ( 76.7%).The mean resistive index of liver cancer group was much higher than that of benign lesion group before and after contrast-enhancement.The accuracy rate for diagnosing liver tumors was raised from 66.7% (84/126) in pre-enhancement to 94.4% (119/126) in post-enhancement.Conclusions The contrast-enhanced color Doppler ultrasonography is very useful in the differential diagnosis of liver tumors.

Objective To evaluate the feasibility of virtual touch tissue quantification (VTQ) for the assessment of renal allograft.Methods A total of 72 kidney recipients were examined with conventional ultrasound and VTQ after transpantation.Biopsies were performed in 34 patients,20 patients were with acute rejection (AR),14 with chronic allograft nephropathy (CAN),38 patients as control group.The peak systolic velocity (PSV) and resistance index(RI) were measured on main,infrarenal and arcuate arteries with conventional ultrasound and shear wave velocity (SWV) of the renal cortex was obtained by VTQ.All the data were compared among three groups.Results There were no significant differences of PSV between two groups.An increased RI was presented in the CAN group(P ＜0.05).The mean SWV was (2.67 ± 0.27) m/s,(2.90 ± 0.31)m/s and (2.28 ± 0.24)m/s for AR,CAN and normal group,respectively.There were significant differences of SWV among the three groups (P ＜ 0.05).Conclusions VTQ technique could provide a new method for the assessment of transplanted kidney.

Objective To probe the correlation between the short-axis diameter(SD) of microwave coagulation and the time(T) and/or power(P) using a new type of internally cooled microwave antenna. Methods A MTC-3 microwave apparatus with a new type of internally-cooled microwave antenna was used to coagulate a fresh porcine liver in vitro. The correlation was analyzed between the SD of coagulation necrosis and the time and/or power. Results ①Under the same power, there was high linear relationship(r= 0.94- 0.98,P

Objective To probe the correlation between the short-axis diameter(SD) of coagulation necosis and the microwave power(P) using a new type of internally cooled microwave antenna in ex vivo and in vivo liver model.Methods Fourteen microwave ablations were performed in swine livers ex vivo and canine livers in vivo under the microwave powers of 30-90W and the durations of 10 min and 20 min, respectively.The short-axis diameter(SD) and the long-axis diameter(LD) of the coagulation were measured.The difference of SD, LD and SD/LD in swine liver ex vivo and canine liver in vivo were compared.The relationship between the SD and microwave power was analysised using linear regression model.Results Under the same conditions,the SDs and LDs of the coagulations of canine livers in vivo were smaller than those of swine livers in ex vivo (P <0.01).There was such a higher linear relationship(r = 0.96-0.99, P <0.01) between the SD of coagulation and the power in vivo liver model as the results acquired in ex vivo.Conclusions Although the blood flow decreased the SDs of the coagulation of microwave ablation in liver in vivo, but there was still a higher linear relationship between SD and microwave power.

Objective To explore the potential value of contrast-enhanced ultrasonography (CEUS) in diagnosis of renal pelvic carcinoma. Methods The ultrasonogram of conventional ultrasound and CEUS were analyzed retrospectively in 22 patients of renal pelvic carcinoma proved pathologically. The size, echo, boundary and color flow signal of renal pelvic lesions were observed with conventional ultrasound. The enhancement modality and phase of tumors were also observed with CEUS, including wash-in and wash-out time, as well as the perfusion appearances. Results The maximum diameters ranged from 1.5 cm to 8.5 cm in 22 renal pelvic tumors. Conventional ultrasound detected flat mass in 7 tumors, irregular mass in 15 tumors; the same side hydronephrosis in 11 patients. Color Doppler flow imaging (CDFI) disclosed fairly rich flow signal of 5 tumors, a small amount of flow signal around tumor in 9 tumors and no-flow signal in the rest tumors. CEUS detected the cortical phase enhancement in all renal pelvic tumors, including synchronously enhancement in 8 tumors and delayed enhancement in 14 tumors. In peak time, hypoechogenicity compared to the normal renal cortex was showed in 18 tumors, hyperechogenicity in 3 tumors and isoechogenicity in 1 tumor. Fast wash-out in medulla phase was displayed in 20 tumors, isochronously wash-out in 1 tumor and delayed wash-out in 1 tumor. The diagnostic accuracy of the conventional ultrasound and CEUS was 63.64% (14/22) and 81.82% (18/22), respectively. Conclusion CEUS can depict blood flow supply and improve the diagnostic rate of renal pelvic carcinoma.

Objective To assess the value of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of focal liver lesions before microwave ablation. Methods One hundred and seven patients with 128 focal liver lesions underwent CEUS and color Doppler flow imaging (CDFI) before microwave ablation therapy. The diagnostic performance of CEUS and CDFI was compared with pathologic findings through biopsy. Results The sensitivity, specificity, positive and negative predictive value, accuracy of CEUS for diagnosing liver lesions was 98.35% (119/121), 100% (7/7), 100% (119/119), 77.78% (7/9) and 98.44% (126/128), respectively, higher than those of CDFI (P＜0.001). According to CEUS, 119 malignant lesions were treated with timely microwave ablation, while unnecessary microwave ablation was excluded for 7 benign lesions. Conclusion CEUS is useful in the characterization of focal liver tumors before microwave ablation, and is helpful to reduce the misdiagnosis and mistreatment of the patients.

Objective To evaluate the diagnostic value of virtual touch tissue quantification (VTQ) in the diagnosis of renal allograft fibrosis.Methods The renal allografts of 82 patients with biopsies or nephrectomy were assessed by virtual touch quantification.The renal allograft fibrosis was categorized according to the 2005 updated Banff criteria for a G0～G3 grade.All the results were compared among four groups.Results The mean SWV values in G0～G3 were (2.39 ± 0.31)m/s,(2.45 ± 0.34)m/s,(2.58 ± 0.18) m/s,(3.11 ± 0.40)m/s,respectively.There were no significant differences in the mean SWV value between G0 and G1 group,or between G1 and G2 group(P ＞0.05).There were significant differences in the mean SWV value between G0～G2 and G3 group,or between G0 and G2 group(P ＜0.05).Stiffness of renal allograft was significantly correlated to the mean SWV value (Spearman r =0.671,P ＜0.001).According to the area under the ROC curve,the sensitivity and specificity of SWV (area under ROC curve =0.847,cut-off=2.64 m/s) for grade ≥G2 was 78.9％ and 79.5％ respectively.Conclusions Stiffness measured by VTQ reflects the interstitial fibrosis in renal allograft.VTQ technique might be a new tool to identify patients with chronic allograft injury.

Objective To evaluate the value of quantitative analysis of contrast‐enhanced ultrasonography (CEUS) in differentiating acute rejection(AR) from acute tubular necrosis(ATN) of transplant kidney. Methods Total of 67 kidney recipients were examined with conventional US and CEUS. Biopsies were performed in 37 patients, 26 patients were with AR, 11 with ATN, 30 patients as control group. The hemodynamic parameters (PSV and RI) were measured on infrarenal artery with conventional US, while CEUS quantitative analysis was performed on the cortex, pyramid and interlobar artery by time‐intensity curve (TIC). TIC parameters including rise time (RT ), time to peak (TTP), mean transit time (mTT ) were compared among three groups. In addition, the reproducibility of TIC parameters was evaluated. Results The RI in AR group was significantly higher than that in control group, but there were no significant differences of RI between AR and ATN groups. TIC parameters including RT, TTP were with high reproducibility (ICC> 0 7.5). Compared to the other two groups, the RT and TTP of the pyramid, ΔRTm‐c, and ΔTTPm‐c were significantly longer in AR group, the receiver operating curves (ROC) analysis demonstrated that ΔRTm‐c had the highest accuracy and RI had the lowest accuracy for detecting AR(areas under the curve were 0 7.86, 0 7.56, 0 7.49, 0 7.36 and 0 4.98, respectively). High sensitivity and specificity(78 3.% and 73 5.%, respectively) were shown when using 4 6.2 s as a cutoff point of ΔRTm‐c to diagnose AR. Conclusions Quantitative analysis of CEUS could detected the changes of the microcirculation perfusion in kidney grafts with AR and ATN, which might be superior in the diagnosis of AR compared with conventional US.

Objective To investigate the viability of analysis of hemodynamic changes with color Doppler flow imaging in the prediction of acute rejection in transplanted liver.Methods Sixty-eight patients enrolled in the study were categorized into three groups:transplanted liver without acute rejection [rejection activity index(RAI) 0-3,n =24],transplanted liver with mild acute rejection (RAI 4-5,n =23),transplanted liver with moderate and severe acute rejection (RAI 6-9,n =21).All the patients were confirmed by pathology.The color Doppler flow imaging were performed in all the patients within 24 hours and 1 week after biopsy.Results In transplanted liver with moderate and severe acute rejection,the peak systolic velocity of portal vein (PV-PSV) was (31.4 ± 14.1)cm/s,significantly lower than that in transplanted liver without acute rejection,which was (45.1 ± 17.7)cm/s (P ＜0.05).A week later after steroid therapy,the PV-PSV in transplanted liver with moderate and severe rejection was increased to (46.7 ± 21.8)cm/s(P ＜0.05).Patients with acute rejection were associated with the decrease of the PVPSV (P ＜0.05).Conclusions The decrease of PV-PSV may have some clinical value in evaluation the acute rejection in transplanted liver.

Objective To compare enhancement features of primary hepatocellular carcinoma(PHCC)and recurrent hepatocellular carcinoma(RHCC) on.contrast-enhanced ultrasonography(CEUS). Methods CEUS was performed in 56 patients with 70 RHCC and 83 patients with 93 PHCC. The enhancement features of these two groups of hepatocellular carcinoma were compared. The time used for the enhancement material to arrive the lesion(Ta ), that used for the lesion to become isoechoic(T1 ) and hypoechoic relative to the surrounding hepatic parenchyma(To) were analyzed. The echogenicity change between the lesion and the parenchyma was observed during arterial phase,portal phase and delayed phase. Results The time used for the lesion to become hypoechogenicity of RHCC and PHCC was (104.0 ± 51.8)s, (85.5 ± 43.0)srespectively,there was significant difference between the two groups( P = 0.010). There were 24 (34.3 % )cases of RHCC and 16 ( 17.2% ) cases of PHCC becoming isoechoic during portal phase,the former rate was significantly higher than the later one( P = 0. 012). Conclusions There is significant difference between PHCC and RHCC in the performance of CEUS,this is useful for the early diagnosis of RHCC.